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Cushman Hydro Project

Cushman No. 1 Dam was one of the first major dams in the Pacific Northwest. It was symbolically activated in 1926 when President Calvin Coolidge pressed a button in the White House during a ceremony to energize the project.

Located on the North Fork of the Skokomish River near Hood Canal, the dam is 275 feet high and 1,111 feet long and generates enough electricity for about 10,000 homes. The dam created Lake Cushman.

Just downstream is Cushman No. 2 Dam, which was completed in 1930, and formed the 150-acre Lake Kokanee. The dam is 235 feet high above bedrock and 575 feet long. Its powerhouse sits several miles below the dam, overlooking Hood Canal along U.S. Highway 101. The dam generates enough energy to power more than 18,000 homes. We added the North Fork Powerhouse in 2013, which generates enough energy to power approximately 1,700 homes.

Our clean, renewable hydroelectric energy moves from the Cushman Hydro Project to Tacoma on a 40-mile-long transmission line. Stretching the line across the Tacoma Narrows in 1926 was a notable engineering achievement at the time. It spans more than a mile and a quarter between towers in Tacoma and Gig Harbor. The original all-steel conductors were replaced with steel reinforced aluminum conductors in 2007.

Cushman Hydro Project map

Project Licensing

All four of our hydroelectric projects are licensed separately by the Federal Energy Regulatory Commission (FERC), which was created by the Federal Power Act to ensure safe and efficient operation of power plants across the U.S. Many other agencies, tribes, organizations and stakeholders are also an important part of the licensing process.

In 2010, FERC amended the Cushman Hydroelectric Project license issued in 1998 to include the terms of a settlement agreement that Tacoma Power and other government agencies signed with the Skokomish Tribal Nation in January 2009. The license allows Tacoma Power to operate the Cushman Hydro Project until 2048.

Settlement Agreements

On Jan. 12, 2009, Tacoma Power, the Skokomish Tribal Nation and state and federal agencies signed a settlement agreement that resolved a $5.8 billion damages claim and long-standing disputes over the terms of an extended license for the Cushman Hydroelectric Project. For details, see the information below:

Fish and Wildlife Programs and Public Recreation

Along with generating clean, renewable hydroelectric energy, our FERC license includes mandates for:

Protecting more than 2,700 acres of healthy habitat for elk, deer, eagles, osprey, wood ducks and a variety of other wildlife.
Public recreation at Lake Cushman, a 4,010-acre reservoir located on the southwestern border of Olympic National Park. The lake has kokanee and cutthroat trout, making it a popular destination for anglers.
Public recreation at Lake Kokanee.
Learn more about our programs for Cushman fisheries and wildlife and recreation.

Take a Tour

Free group tours of the Cushman Hydro Project facilities are available by appointment for school, civic, business and recreational groups during regular working hours. Tour groups meet at the Cushman Powerhouse No. 2, located on Highway 101 near the town of Potlatch, south of Hoodsport.

To make arrangements for a tour, please complete our request form.

Statistics

Cushman No. 1 Dam

Year completed – 1926
River system – North Fork, Skokomish River
Original investment – $4.26 million
Type of dam – concrete arch/gravity and embankment
Height – above riverbed, 235 feet; above bedrock, 275 feet
Length – 1,111 feet
Width – top, 8 feet; base, 50 feet
Volume of concrete in dam – 90,000 cubic yards
Average flow – 845 cubic feet/second
Drainage area – 94 square miles
Reservoir length – 9.6 miles
Miles of shoreline – 23 miles
Reservoir area at maximum elevation – 4,010 acres
Reservoir elevation – full, 738 feet; lowest allowable, 615 feet
Average annual generation – 127 million kilowatt-hours
Equivalent number of NW homes served – 10,000
Number of generators – two 25,000 kilowatt generators
Installed capacity (nameplate rating) – 50,000 kilowatts

Cushman No. 2 Dam and North Fork Skokomish Powerhouse

Year completed – 1930
River system – North Fork, Skokomish River
Original investment – $8.23 million
Type of dam – concrete arch/gravity
Height – above riverbed, 175 feet; above bedrock, 235 feet
Length – 575 feet
Width – top, 8 feet; base, 40 feet
Volume of concrete in dam – 38,000 cubic yards
Average flow – 852 cubic feet/second
Drainage area – 100 square miles
Reservoir length – 2 miles
Miles of shoreline – 4.5 miles
Reservoir area at maximum elevation – 150 acres
Reservoir elevation – full, 480 feet; lowest allowable, 460 feet
Average annual generation – 233 million kilowatt-hours
Equivalent number of NW homes served – 18,500
Number of generators – three 27,000 kilowatt generators
Installed capacity (nameplate rating) – 81,000 kilowatts

North Fork Skokomish Powerhouse

Year completed – 2013
Average annual generation – 22 million kilowatt-hours
Equivalent number of NW homes served – 1,700
Number of generators – two 1,800 kilowatt generators
Installed capacity (nameplate rating) – 3,600 kilowatts

Latest News

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Please send questions/comments to: cushman@cityoftacoma.org.
For questions about the Staircase Road paving project, please email marjorie.hutchinson@usda.gov.

Staircase Road received second dust control treatment on Aug. 16
Tacoma Power voluntarily provided a second application of the temporary dust control treatment on the first mile of Staircase Road on Aug. 16. A second treatment is not generally anticipated but is sometimes necessary if the first application is not successful due to environmental conditions.

The second treatment was delayed due to a challenge in obtaining the dust control material. The local source for it closed, and the only available source now is from an east coast company that transports it via rail.

Please send questions/comments to: cushman@cityoftacoma.org. For questions about the Staircase Road paving project, please email marjorie.hutchinson@usda.gov.

Many happy returns: Sockeye come home to Cushman for the first time in 90 years

Fisheries technician Charlie Henry and our first returning sockeye

July 7, 2020, was a day to mark on the calendar for our Cushman fisheries program: our first-ever sockeye returned home!

“We have been patiently waiting since we released our first sockeye into Lake Cushman three years ago,” said Cushman Fish Facilities Manager Andrew Ollenburg. “When I heard the exciting news, I was buzzing – it was super awesome.”

The Cushman Hydroelectric Project provides clean, renewable electricity via two dams and three powerhouses. However, when the dams were built, they impacted the river and the natural environment.

As part of our federal license to operate the dams, we invested in two hatcheries, adult and juvenile collection facilities, and enhanced fish and habitat monitoring and evaluation programs.

“That fish doesn’t just represent our first sockeye return, that fish is the first one that has touched every Cushman facility,” Andrew said. “Starting at the hatchery, to Lake Cushman, to our juvenile fish collector, to being trucked down to our sorting facility, being sent out into the river via our release tube, returning from the ocean, navigating over Little Falls and ending up in our adult trap, being brought back up to the sorting facility via our tram, then being trucked over to our hatchery. That fish completed the full cycle.”

Sourcing the eggs

Our release goal for sockeye is 2,000,000 each year, but obtaining the eggs has been a challenge.

“Puget Sound Energy’s Baker Lake stock provides us with the eggs, but, due to scarcity issues, they have only been able to provide 250,000 to 500,000 eggs per year, and this year they won’t be able to provide any,” Andrew said. “They are our only option – no other basin that has a large-enough run that could spare any. Thankfully, we had 127 fish return, about half of which are female, so we should have roughly 100,000 eggs.”

Mark it up

The sockeye hatchery has an ultramodern computer-controlled chiller system that enables us to thermally mark sockeye via their otolith bone, located in the ear.

“We don’t know of any other hatchery that has the same level of automated control to mark groups at these granular levels, so our partners are excited to see the data we collect,” Andrew said. “We work in conjunction with the Skokomish Indian Tribe, Puget Sound Energy, natural resource agencies and other stakeholders. These relationships are extremely important to us and to the program’s success.”

Setting up for success

Determining which test groups have the highest survival rates will take time and patience.

“We should have enough data within about five years to know how to set our fish up for the best possible success,” Andrew said.

Andrew says it’s important to remember our role in the basin.

“We don’t decide who gets to fish for what, where, or when – those decisions are made by the Tribes and the Washington Department of Fish and Wildlife,” Andrew said. “Our goal is to be a responsible steward of the environment by reintroducing and restoring fish populations, and this sockeye return is another huge leap toward making that happen.”

Public Meetings

Cushman Hydro Project Update – Sept. 12, 2019
Cushman Fire Hall | 5 to 7 p.m.
Approximately 33 attendees

Agenda

Presentations:

USFS Fact Sheet for Staircase Road – September 2019

Cushman Shoreline Management Plan Update – Sept. 20, 2019
Cushman Fire Hall | 4 to 6 p.m.
Approximately 75 attendees

Get more shoreline permitting information at MyTPU.org/CushmanShoreline